A magnetic head and disk tester is an instrument that is used for testing the characteristics of magnetic heads and disks such as signal-to-noise ratio, pulse width and so on. Each tester includes two main assemblies, i.e., an electro-mechanical assembly that performs movements of a head assembly with respect to a disk, and an electronic assembly that is responsible for measurements, calculations, and analysis of the measured data.
In many known magnetic head and disk testers linear movements are used to achieve proper positioning of a magnetic head with respect to a magnetic disk mounted on a disk spindle. For example, the magnetic head and disk tester disclosed in U.S. Pat. No. 4,902,971 to Guzik et al. uses only one (X-axis) movement. As a result, a proper skew angle is achieved only on inner and outer tracks. On other tracks the skew angle is close but not equal to the required value.
Positioning mechanisms employing linear X-Y movements are also utilized in the field of magnetic head and disk testing, for instance in the E5013A spin stand by Agilent Technologies. These mechanisms use separate sliders on X and Y-axes. The main disadvantage of known X-Y positioning mechanism is the strict demands this method impose on the control of head moving mechanism. For instance, as explained below, it may require a complex geometrical path over which the head travels across the surface of the disk. In some situations no simple mechanical provisions exist to prevent the head from crashing into the hub of the disk spindle.